This invention relates to an enclosed-type compressor, and more particularly, to a vertical-type reciprocatable enclosed compressor provided with a frame supporting component element, which is an improvement of a U.S. Pat. No. 4,566,865 issued on Jan. 28, 1986, from an application filed July 29, 1983 by K. NISHITSUZI et al and assigned to the same applicant as that of the subject application.
U.S. Pat. No. 4,566,865 discloses a vertical type enclosed compressor wherein an electric motor and a compression mechanism are supported in an enclosing type casing by a frame member made of a metal plate. More specifically as shown in FIG. 1, a cylinder 3 of the compression mechanism 2 and a main bearing 4 that rotatably supports a driving shaft 6 of the electric motor, not shown, are secured to a frame member 1 made of, for instance, a steel plate, by respective sets of securing means such as bolts 5a and 5b which are driven into the frame member 1 at positions radially spaced apart with respect to the center line of the driving shaft 6 or the main bearing 4. That is, the positions at which the cylinder 7 is secured to the frame 1 by means of a set of bolts 5a are radially outwardly spaced apart from the positions at which the main bearing 4 is secured to the frame member 1 by means of a set of bolts 5b.
In the above described construction of the conventional enclosed type compressor, when a piston 7 of the compression mechanism is reciprocated in the cylinder 3, a reaction force caused by the compressing movement of the piston 7 creates a bending moment M applied to the frame member 1 as shown in FIG. 2. In order to withstand the bending moment M, a considerable rigidity is required in the part of the frame member 1 supporting the compression mechanism and the electric motor.
However, the rigidity of the frame 1 made of a steel plate is substantially lower than that of a frame made by metal casting, and the rigidity is further reduced in a region between A and B (of a distance l) where the cylinder 3 and the main bearing 4 are secured to the frame 1, respectively. The reduction in turn reduces the rigidity of the entire frame 1, and causes a deviation in the clearance between the stator and rotor of the electric motor. The deviation in the clearance in turn impairs the starting characteristics and stability in operation of the electric motor, thus reducing the reliability of the electric motor.